Experimental setup. (A) Schematic diagram of the experimental setup. Abbreviations are: P, phase plate with polarizer; A, analyzer; MO, stepping motor; CON, condenser lens; OBJ, objective lens; QPD, quadrant photodiode; PL, PowerLab; PC, personal computer; CCD, CCD camera; DV, digital video recorder; M, mirror. The light was split into beams (80% and 20%) by the half-mirror (HM). For more details, see Materials and Methods. (B) A bright-field image showing a configuration of the dual laminar flow and the myofibril. The dual laminar flow was infused from the right-hand side through the θ-capillary. The dye was included in the bottom flow to visualize the laminar flow. The needles on the upper side (having a perpendicularly bent tip) and on the left side of the micrograph are the stiff and the flexible, respectively. The myofibrils are held between the microneedles. Scale bar, 200 μm.